When trying to trigger a build of a branch job of a *disabled* Multibranch project, the build is not scheduled (because the multibranch is disabled) but a UI notification pop up shows "Build Scheduled".

Note: The developer console shows that the request to /build?delay=0 returns a 302. Whereas in a case where the build is actually scheduled we get a 201.

How to Reproduce

• Create a Multibranch pipeline
• Disable the Multibranch Pipeline (through its configuration page or /disable)
• try to build a branch job